Purely electrically-propelled vehicles are increasingly being used, notably in urban areas. The use of electric vehicles offers numerous advantages. The batteries are critical components for these types of vehicles. More generally, the management of the energy for these vehicles presents issues totally different from those for thermally-powered vehicles propelled by fossil fuels.
In particular, the batteries carried onboard electric vehicles have a finite energy capacity. Furthermore, the electrical recharging of a battery requires a significant amount of time. Consequently, it is essential for the driver of such a vehicle to be sure that the quantity of energy stored in the batteries is sufficient for covering a desired distance while at the same time activating the auxiliary equipment which ensures the comfort of the passengers.
For thermally-powered vehicles, the question of the management of the auxiliary equipment (heating, air conditioning, etc. . . . ) is not posed since fossil fuel is available over the road network at numerous refueling points. Thus, the strategy for management of the auxiliaries boils down to satisfying the requirements of the driver. In the case of electric vehicles, this simple strategy can quickly become unfeasible. The storage capacities are limited and the recharging points currently absent. Satisfying at any price the desired level of comfort (via the auxiliaries for heating, radio, etc.) can quickly use up the energy resources of the battery. This can happen to the detriment of the objective of the mission which is to arrive at the destination of the journey.
Coming up with a strategy for energy management taking into account the minimization of the energy consumed, the constraint of arriving at the destination and satisfying the comforts can become challenging for the driver. Indeed, these criteria can effectively impose a very slow mode of driving and the non-compliance with the speed requirements of the driver.
Numerous articles offer solutions for implementing systems for management of the energy in hybrid vehicles, with thermal engines and electric motors. These systems are furthermore called EMS, an acronym for “Energy Management Systems”. The term EMS will be used henceforth.
As a general rule, these articles offer energy management strategies with the aim of finding the best scenario for activation of the thermal engine and/or electric motor at a given moment in time with regard to criteria linked to the consumption and/or pollutant emissions from a vehicle. These strategies do not allow, at the same time, the management of the satisfaction of the comfort indices of the vehicles, notably the demands from the auxiliary equipment, the electrical consumption of the battery and the performance indices of the vehicles, such as the journey time for example, in the case of a purely electrical propulsion.
Within the field of energy management for purely electrically-propelled vehicles, the patent application EP1462300 A1 may be mentioned. In this document, the aim is to allow the management of the level of charge and discharge of the battery by the driver by virtue of certain information given to the driver of the vehicle. One drawback of the solution provided is that it requires the use of a battery charger, which is a serious constraint.